The Gunners have struggled defensively throughout the 2017-18 season so far in all competitions.
Arsenal have conceded 41 times in 30 games in the current Premier League campaign to contribute to their poor performances.
The Gunners have only managed to win three of their 15 games on the road in the England top flight to leave Arsenal in sixth spot.
The north London side lost 4-2 to Championship side Nottingham Forest in the FA Cup third round back in January.
Arsenal suffered a resounding 3-0 defeat by Premier League leaders Manchester City in the League Cup final at Wembley.
Henrikh Mkhitaryan completed a move to the Emirates Stadium from their Premier League rivals Manchester United in the January transfer window.
The Gunners signed Pierre-Emerick Aubameyang in a club record £56m deal from Borussia Dortmund on transfer deadline day.
Former Chelsea FC midfielder Lampard believes Arsenal need to sign a commanding defender to bolster Wenger’s back four this summer.
“They need that strong man at the back who can defend well enough because they’ve shown in that bad run they’ve had that they were making mistake after mistake,” Lampard told BT Sport.
“Sometimes you have to look at individuals.”
Arsenal haven’t won the Premier League title since 2003-04 when Wenger was able to call upon talented players such as Thierry Henry, Robert Pires and Patrick Vieira.
The Gunners have won the FA Cup in three of the past four seasons.
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